From 2fc7f252eff9fb45f6f3416dbc47c21c7fa5e892 Mon Sep 17 00:00:00 2001 From: Kovid Goyal Date: Fri, 11 Oct 2024 21:00:45 +0530 Subject: [PATCH] Work on function for transcoding of audio stream --- setup/extensions.json | 2 +- src/calibre/utils/ffmpeg.c | 351 ++++++++++++++++++++++++++++++++++++- 2 files changed, 349 insertions(+), 4 deletions(-) diff --git a/setup/extensions.json b/setup/extensions.json index 7824c01a9b..0cd89933fa 100644 --- a/setup/extensions.json +++ b/setup/extensions.json @@ -19,7 +19,7 @@ { "name": "ffmpeg", "sources": "calibre/utils/ffmpeg.c", - "libraries": "swresample avcodec avutil", + "libraries": "swresample avcodec avformat avutil", "inc_dirs": "!ffmpeg_inc_dirs", "lib_dirs": "!ffmpeg_lib_dirs", "needs_c": "99" diff --git a/src/calibre/utils/ffmpeg.c b/src/calibre/utils/ffmpeg.c index d9258b6b4b..6279440c94 100644 --- a/src/calibre/utils/ffmpeg.c +++ b/src/calibre/utils/ffmpeg.c @@ -26,12 +26,354 @@ static PyObject* averror_as_python(int errnum, int line) { - char avbuf[4096]; - av_strerror(errnum, avbuf, sizeof(avbuf)); - PyErr_Format(PyExc_Exception, "%s:%d:%s", __FILE__, line, avbuf); + if (!PyErr_Occurred()) { // python error happened in a callback function for example + char avbuf[4096]; + av_strerror(errnum, avbuf, sizeof(avbuf)); + PyErr_Format(PyExc_Exception, "%s:%d:%s", __FILE__, line, avbuf); + } return NULL; } +typedef struct Transcoder { + AVCodecContext *dec_ctx, *enc_ctx; + AVFrame *dec_frame; + AVFormatContext *ifmt_ctx, *ofmt_ctx; + AVIOContext *input_ctx, *output_ctx; + AVPacket *pkt; + PyObject *write_output, *read_input, *seek_in_input, *seek_in_output; + unsigned int output_bitrate; + const char *container_format, *output_codec_name; + AVAudioFifo *fifo; + SwrContext *resample_ctx; + int64_t pts; +} Transcoder; + +#define check_call(func, ...) if ((ret = func(__VA_ARGS__)) < 0) return averror_as_python(ret, __LINE__); + +static int +read_packet(void *opaque, uint8_t *buf, int buf_size) { + PyObject *psz = PyLong_FromLong((long)buf_size); + PyObject *ret = PyObject_CallOneArg(((Transcoder*)opaque)->read_input, psz); + Py_DECREF(psz); + if (!ret) return AVERROR_EXTERNAL; + Py_buffer b; + if (PyObject_GetBuffer(ret, &b, PyBUF_SIMPLE) != 0) return AVERROR_EXTERNAL; + memcpy(buf, b.buf, b.len < buf_size ? b.len : buf_size); + Py_DECREF(ret); PyBuffer_Release(&b); + return b.len; +} + + +static int +write_packet(void *opaque, const uint8_t *buf, int buf_size) { + Transcoder *t = opaque; + PyObject *mv = PyMemoryView_FromMemory((char*)buf, buf_size, PyBUF_READ); + if (!mv) return AVERROR_EXTERNAL; + PyObject *ret = PyObject_CallOneArg(t->write_output, mv); + Py_DECREF(mv); + if (!ret) return AVERROR_EXTERNAL; + int ans = PyLong_AsLong(ret); + Py_DECREF(ret); + return ans; +} + +static int64_t +seek_packet(PyObject *seek_func, int64_t offset, int whence) { + PyObject *ret = PyObject_CallFunction(seek_func, "Li", offset, whence); + if (!ret) return AVERROR_EXTERNAL; + long long ans = PyLong_AsLongLong(ret); + Py_DECREF(ret); + return ans; +} + +static int64_t +seek_packet_input(void *opaque, int64_t offset, int whence) { return seek_packet(((Transcoder*)opaque)->seek_in_input, offset, whence); } + +static int64_t +seek_packet_output(void *opaque, int64_t offset, int whence) { return seek_packet(((Transcoder*)opaque)->seek_in_output, offset, whence); } + +static PyObject* +open_input_file(Transcoder *t) { + if (!(t->ifmt_ctx = avformat_alloc_context())) { PyErr_NoMemory(); return NULL; } + static const size_t io_bufsize = 8192; + uint8_t *input_buf; + if (!(input_buf = av_malloc(io_bufsize))) { PyErr_NoMemory(); return NULL; } + if (!(t->input_ctx = avio_alloc_context(input_buf, io_bufsize, 0, t, &read_packet, NULL, &seek_packet_input))) { PyErr_NoMemory(); return NULL; } + t->ifmt_ctx->pb = t->input_ctx; + int ret; + check_call(avformat_open_input, &t->ifmt_ctx, NULL, NULL, NULL); + check_call(avformat_find_stream_info, t->ifmt_ctx, NULL); + if (t->ifmt_ctx->nb_streams != 1) { + PyErr_Format(PyExc_ValueError, "input file must have only one stream, it has: %u streams", t->ifmt_ctx->nb_streams); return NULL; + } + const AVStream *stream = t->ifmt_ctx->streams[0]; + const AVCodec *input_codec = avcodec_find_decoder(stream->codecpar->codec_id); + if (!input_codec) { + PyErr_SetString(PyExc_ValueError, "could not find codec to decode input file"); return NULL; + } + if (!(t->dec_ctx = avcodec_alloc_context3(input_codec))) return PyErr_NoMemory(); + check_call(avcodec_parameters_to_context, t->dec_ctx, stream->codecpar); + check_call(avcodec_open2, t->dec_ctx, input_codec, NULL); + t->dec_ctx->pkt_timebase = stream->time_base; + return Py_True; +} + +static PyObject* +open_output_file(Transcoder *t) { + if (!(t->ofmt_ctx = avformat_alloc_context())) { PyErr_NoMemory(); return NULL; } + static const size_t io_bufsize = 8192; + uint8_t *input_buf; + if (!(input_buf = av_malloc(io_bufsize))) { PyErr_NoMemory(); return NULL; } + if (!(t->output_ctx = avio_alloc_context(input_buf, io_bufsize, 0, t, NULL, &write_packet, &seek_packet_output))) { PyErr_NoMemory(); return NULL; } + t->ofmt_ctx->pb = t->output_ctx; + + if (!(t->ofmt_ctx->oformat = av_guess_format(t->container_format, NULL, NULL))) { + PyErr_Format(PyExc_KeyError, "unknown output container format: %s", t->container_format); return NULL; + } + const AVCodec *output_codec = NULL; + if (!t->output_codec_name[0]) { + if (!(output_codec = avcodec_find_encoder(t->ofmt_ctx->oformat->audio_codec))) { + PyErr_Format(PyExc_RuntimeError, "Default audio output codec for %s not available", t->ofmt_ctx->oformat->long_name); return NULL; + } + } else { + if (!(output_codec = avcodec_find_encoder_by_name(t->output_codec_name))) { + PyErr_Format(PyExc_KeyError, "unknown output codec: %s", t->output_codec_name); return NULL; + } + } + AVStream *stream = NULL; + if (!(stream = avformat_new_stream(t->ofmt_ctx, NULL))) return PyErr_NoMemory(); + if (!(t->enc_ctx = avcodec_alloc_context3(output_codec))) return PyErr_NoMemory(); + + // Setup encoding parameters + av_channel_layout_default(&t->enc_ctx->ch_layout, t->dec_ctx->ch_layout.nb_channels); + t->enc_ctx->sample_rate = t->dec_ctx->sample_rate; + t->enc_ctx->sample_fmt = output_codec->sample_fmts[0]; + t->enc_ctx->bit_rate = t->output_bitrate; + if (!t->enc_ctx->bit_rate) { + switch (output_codec->id) { + case AV_CODEC_ID_AAC: t->enc_ctx->bit_rate = 96; break; + case AV_CODEC_ID_MP3: t->enc_ctx->bit_rate = 192; break; + default: t->enc_ctx->bit_rate = 128; + } + t->enc_ctx->bit_rate *= 1000 * t->enc_ctx->ch_layout.nb_channels; + } + stream->time_base.den = t->dec_ctx->sample_rate; + stream->time_base.num = 1; + if (t->ofmt_ctx->oformat->flags & AVFMT_GLOBALHEADER) t->enc_ctx->flags |= AV_CODEC_FLAG_GLOBAL_HEADER; + int ret; + check_call(avcodec_open2, t->enc_ctx, output_codec, NULL); + check_call(avcodec_parameters_from_context, stream->codecpar, t->enc_ctx); + return Py_True; +} + +static PyObject* +add_samples_to_fifo(AVAudioFifo *fifo, uint8_t **converted_input_samples, const int frame_size) { + int ret; + + /* Make the FIFO as large as it needs to be to hold both, + * the old and the new samples. */ + check_call(av_audio_fifo_realloc, fifo, av_audio_fifo_size(fifo) + frame_size); + /* Store the new samples in the FIFO buffer. */ + if (av_audio_fifo_write(fifo, (void **)converted_input_samples, frame_size) < frame_size) { + PyErr_SetString(PyExc_Exception, "could not write data to FIFO"); return NULL; + } + return Py_True; +} + +static PyObject* +decode_audio_frame(AVFrame *input_frame, AVFormatContext *input_format_context, AVCodecContext *input_codec_context, bool *data_present, bool *finished) { + AVPacket *input_packet = av_packet_alloc(); + if (!input_packet) return PyErr_NoMemory(); + *data_present = false; + *finished = false; + int ret; + PyObject *r = NULL; + if ((ret = av_read_frame(input_format_context, input_packet)) < 0) { + if (ret == AVERROR_EOF) *finished = 1; + else { averror_as_python(ret, __LINE__); goto cleanup; } + } + Py_BEGIN_ALLOW_THREADS; + ret = avcodec_send_packet(input_codec_context, input_packet); + Py_END_ALLOW_THREADS; + if (ret < 0) { averror_as_python(ret, __LINE__); goto cleanup; } + Py_BEGIN_ALLOW_THREADS; + ret = avcodec_receive_frame(input_codec_context, input_frame); + Py_END_ALLOW_THREADS; + if (ret == AVERROR(EAGAIN)) { r = Py_True; goto cleanup; } + if (ret == AVERROR_EOF) { r = Py_True; *finished = true; goto cleanup; } + if (ret < 0) { averror_as_python(ret, __LINE__); goto cleanup; } + *data_present = true; +cleanup: + av_packet_free(&input_packet); + return r; +} + +static PyObject* +read_decode_convert_and_store(Transcoder *t, bool *finished) { + PyObject *r = NULL; + int ret; + AVFrame *input_frame = av_frame_alloc(); + uint8_t **converted_input_samples = NULL; + if (!input_frame) { PyErr_NoMemory(); goto cleanup; } + bool data_present = false; + if (!decode_audio_frame(input_frame, t->ifmt_ctx, t->dec_ctx, &data_present, finished)) goto cleanup; + if (*finished) { r = Py_True; goto cleanup; } + if (data_present) { + // Convert the samples to the format needed by the encoder + if ((ret = av_samples_alloc_array_and_samples( + &converted_input_samples, NULL, t->enc_ctx->ch_layout.nb_channels, + input_frame->nb_samples, t->enc_ctx->sample_fmt, 0)) < 0) { averror_as_python(ret, __LINE__); goto cleanup; } + Py_BEGIN_ALLOW_THREADS; + ret = swr_convert(t->resample_ctx, converted_input_samples, input_frame->nb_samples, (const uint8_t**)input_frame->extended_data, input_frame->nb_samples); + Py_END_ALLOW_THREADS; + if (ret < 0) { averror_as_python(ret, __LINE__); goto cleanup; } + // Add the converted input samples to the FIFO buffer for later processing. + if (!add_samples_to_fifo(t->fifo, converted_input_samples, input_frame->nb_samples)) goto cleanup; + } + + r = Py_True; +cleanup: + if (converted_input_samples) av_freep(&converted_input_samples[0]); + av_freep(&converted_input_samples); + av_frame_free(&input_frame); + return r; +} + + +static PyObject* +encode_audio_frame(AVFrame *frame, AVFormatContext *output_format_context, AVCodecContext *output_codec_context, bool *data_present, int64_t *pts) { + AVPacket *output_packet = av_packet_alloc(); + if (!output_packet) return PyErr_NoMemory(); + + if (frame) { + frame->pts = *pts; + *pts += frame->nb_samples; + } + *data_present = false; + int ret; + PyObject *r = NULL; + Py_BEGIN_ALLOW_THREADS; + ret = avcodec_send_frame(output_codec_context, frame); + Py_END_ALLOW_THREADS; + if (ret < 0 && ret != AVERROR_EOF) { + averror_as_python(ret, __LINE__); goto cleanup; + } + Py_BEGIN_ALLOW_THREADS; + ret = avcodec_receive_packet(output_codec_context, output_packet); + Py_END_ALLOW_THREADS; + if (ret == AVERROR(EAGAIN)) { + goto ok; + /* If the last frame has been encoded, stop encoding. */ + } else if (ret == AVERROR_EOF) { + goto ok; + } else if (ret < 0) { + averror_as_python(ret, __LINE__); + goto cleanup; + /* Default case: Return encoded data. */ + } else { + *data_present = true; + } + if (*data_present && (ret = av_write_frame(output_format_context, output_packet)) < 0) { + averror_as_python(ret, __LINE__); goto cleanup; + } + +ok: + r = Py_True; + +cleanup: + av_packet_free(&output_packet); + return r; +} + + +static PyObject* +load_encode_and_write(AVAudioFifo *fifo, AVFormatContext *output_format_context, AVCodecContext *output_codec_context, int64_t *pts) { + const int frame_size = FFMIN(av_audio_fifo_size(fifo), output_codec_context->frame_size); + PyObject *r = NULL; + bool data_written = false; + AVFrame *output_frame = av_frame_alloc(); + if (!output_frame) return PyErr_NoMemory(); + output_frame->nb_samples = frame_size; + av_channel_layout_copy(&output_frame->ch_layout, &output_codec_context->ch_layout); + output_frame->format = output_codec_context->sample_fmt; + output_frame->sample_rate = output_codec_context->sample_rate; + int ret = av_frame_get_buffer(output_frame, 0); + if (ret < 0) { averror_as_python(ret, __LINE__); goto cleanup; } + if (av_audio_fifo_read(fifo, (void **)output_frame->data, frame_size) < frame_size) { + PyErr_SetString(PyExc_Exception, "could not read audio data from AVAudioFifo"); goto cleanup; + } + if (!encode_audio_frame(output_frame, output_format_context, output_codec_context, &data_written, pts)) goto cleanup; + r = Py_True; + +cleanup: + if (output_frame) av_frame_free(&output_frame); + return r; +} + + +static PyObject* +transcode_loop(Transcoder *t) { + AVCodecContext *output_codec_context = t->enc_ctx; + while(true) { + const int output_frame_size = output_codec_context->frame_size; + bool finished = false; + while (!finished && av_audio_fifo_size(t->fifo) < output_frame_size) { + if (!read_decode_convert_and_store(t, &finished)) return NULL; + } + while (av_audio_fifo_size(t->fifo) >= output_frame_size || (finished && av_audio_fifo_size(t->fifo) > 0)) { + if (!load_encode_and_write(t->fifo, t->ofmt_ctx, t->enc_ctx, &t->pts)) return NULL; + } + if (finished) { + bool data_written = false; + /* Flush the encoder as it may have delayed frames. */ + do { + if (!encode_audio_frame(NULL, t->ofmt_ctx, t->enc_ctx, &data_written, &t->pts)) return NULL; + } while (data_written); + break; + } + } + return Py_True; +} + +static PyObject* +transcode_single_audio_stream(PyObject *self, PyObject *args, PyObject *kw) { + static char *kwds[] = {"read_input", "seek_in_input", "write_output", "seek_in_output", "output_bitrate", "container_format", "output_codec_name", NULL}; + Transcoder t = {.container_format = "mp4", .output_codec_name = ""}; + if (!PyArg_ParseTupleAndKeywords(args, kw, "OOOO|Iss", kwds, &t.read_input, &t.seek_in_input, &t.write_output, &t.seek_in_output, &t.output_bitrate, &t.container_format, &t.output_codec_name)) return NULL; + if (!PyCallable_Check(t.read_input)) { PyErr_SetString(PyExc_TypeError, "read_input must be callable"); return NULL; } + if (!PyCallable_Check(t.seek_in_input)) { PyErr_SetString(PyExc_TypeError, "seek_in_input must be callable"); return NULL; } + if (!PyCallable_Check(t.write_output)) { PyErr_SetString(PyExc_TypeError, "write_output must be callable"); return NULL; } + if (!PyCallable_Check(t.seek_in_output)) { PyErr_SetString(PyExc_TypeError, "seek_in_output must be callable"); return NULL; } + + if (!open_input_file(&t)) goto cleanup; + if (!open_output_file(&t)) goto cleanup; + if (!(t.fifo = av_audio_fifo_alloc(t.enc_ctx->sample_fmt, t.enc_ctx->ch_layout.nb_channels, 1))) { + PyErr_NoMemory(); goto cleanup; + } + int ret; + if ((ret = swr_alloc_set_opts2(&t.resample_ctx, + &t.enc_ctx->ch_layout, t.enc_ctx->sample_fmt, t.enc_ctx->sample_rate, + &t.dec_ctx->ch_layout, t.dec_ctx->sample_fmt, t.dec_ctx->sample_rate, + 0, NULL)) < 0) { averror_as_python(ret, __LINE__); goto cleanup; } + if ((ret = swr_init(t.resample_ctx)) < 0) { averror_as_python(ret, __LINE__); goto cleanup; } + + if ((ret = avformat_write_header(t.ofmt_ctx, NULL)) < 0) { averror_as_python(ret, __LINE__); goto cleanup; } + if (!transcode_loop(&t)) goto cleanup; + if ((ret = av_write_trailer(t.ofmt_ctx)) < 0) { averror_as_python(ret, __LINE__); goto cleanup; } + +cleanup: + if (t.fifo) { av_audio_fifo_free(t.fifo); t.fifo = NULL; } + if (t.enc_ctx) avcodec_free_context(&t.enc_ctx); + if (t.dec_ctx) avcodec_free_context(&t.dec_ctx); + if (t.ifmt_ctx) { avio_closep(&t.ifmt_ctx->pb); avformat_close_input(&t.ifmt_ctx); } + if (t.ofmt_ctx) { avio_closep(&t.ofmt_ctx->pb); avformat_free_context(t.ofmt_ctx); } + if (t.input_ctx) { av_freep(&t.input_ctx->buffer); avio_context_free(&t.input_ctx); } + if (t.output_ctx) { av_freep(&t.output_ctx->buffer); avio_context_free(&t.output_ctx); } + if (t.resample_ctx) swr_free(&t.resample_ctx); + if (PyErr_Occurred()) return NULL; + Py_RETURN_NONE; +} + // resample_raw_audio_16bit {{{ static PyObject* resample_raw_audio_16bit(PyObject *self, PyObject *args) { @@ -132,6 +474,9 @@ CALIBRE_MODINIT_FUNC PyInit_ffmpeg(void) { {"resample_raw_audio_16bit", (PyCFunction)resample_raw_audio_16bit, METH_VARARGS, "resample_raw_audio(input_data, input_sample_rate, output_sample_rate, input_num_channels=1, output_num_channels=1) -> Return resampled raw audio data." }, + {"transcode_single_audio_stream", (PyCFunction)transcode_single_audio_stream, METH_VARARGS | METH_KEYWORDS, + "transcode_single_audio_stream() -> Transcode an input file containing a single audio stream to an output file in the specified format." + }, {"wav_header_for_pcm_data", (PyCFunction)wav_header_for_pcm_data, METH_VARARGS, "wav_header_for_pcm_data(audio_data_size=0, sample_rate=22050, num_channels=1) -> WAV header for specified amount of PCM data as bytestring" },